Tuesday 7 February 2012 13.31 EST
First published on Tuesday 7 February 2012 13.31 EST

The Argentinian president, Cristina Fernández de Kirchner, has summoned the country's political elite and veterans of the 1982 Falklands war to the presidential palace for what is expected to be a significant announcement about the islands.

The Casa Rosada made the rare gesture of inviting opposition leaders to the Hall of Latin American Patriots for what is speculated to be an escalation in the diplomatic row with Britain over the islands' sovereignty.

Diplomats cleared their schedules for the event, scheduled for 10pm British time, after a week of increasingly heated rhetoric on the south Atlantic archipelago, which Argentina calls Las Malvinas.

Having mobilised much of South America and the Caribbean in its diplomatic and commercial squeeze – ships flying the Falklands flag are barred from the region's ports, depriving the islands of bananas and other fresh fruit – there was speculation Argentina would close its air space to Falklands flights, effectively blockading the civilian population. The weekly service by the Chilean flag-carrier, LAN is the islands' only air link with South America and main connection with the outside world.

In a separate move, the Argentine Football Association is considering a government proposal to name its top division after the General Belgrano, the navy cruiser sunk by a British submarine during the war. It is also due to debate naming the cup "Gaucho Rivero" after Antonio Rivero, a cattle herder feted as a folk hero by some Argentinians for killing five prominent British settlers in 1833 – the year London is accused of stealing the territory.

The diplomatic sparring has intensified in the runup to the 30th anniversary of the war, which started with an Argentinian military occupation on 2 April 1982 and ended 10 weeks later in victory for a British naval task force. Tension flared last year when Argentina protested at oil drilling and London's refusal to discuss sovereignty.

Two weeks ago, Argentina's official news agency, Telam, started a Malvinas page with banner pictures of Argentinian jet fighters, helicopters, tanks and soldiers. Last week Britain dispatched the destroyer HMS Dauntless and Prince William, a search and rescue pilot, claiming both deployments were routine.

A correspondent for the newspaper Clarin reported harsh sentiments from Port Stanley on Tuesday. The article quoted islanders referring to "fucking Argies" and was illustrated with a photograph of a gift shop mug with an altered map of South America that replaced Argentina with blue emptiness named "Mierda Sea". Mierda means "shit" in Spanish.

A senior European diplomat in Buenos Aires said Europe's economic crisis had emboldened Argentina, which was riding high on nine years of strong economic growth. "South America doesn't have the respect it used to have for Europe, it feels it is on top now and is flexing its new muscles."

A summit of leftwing leaders in Venezuela last weekend backed Fernández's campaign as a pan-regional cause. Her Venezuelan counterpart, Hugo Chávez, said Caracas would support its ally in a military conflict. "Thirty years ago Argentina was left on its own, but things have changed. The old dismantled empire should not believe that Argentina is alone because South America is here, Latin America is here." Ecuador's Rafael Correa called for sanctions against Britain.

Argentina's foreign minister, Hector Timerman, welcomed the solidarity. "Argentina is not alone, Great Britain is alone."